Network.Firewall Model
======================

    listModules():
        Lists usable firewall modules.

        Function should return something like that:

        O1 [
        02     "internet-sharing",
        03     "content-serving",
        04 ]


    moduleInfo(module):
        Returns module title, description and icon.

        Function should return something like that:

        O1 (
        02     i18n("Internet Sharing"),
        03     i18n("Description..."),
        04     "network-workgroup"
        05 )


    moduleParameters(module):
        Returns parameters required by module.

        Function should return something like that:

        O1 [
        02     (
        03         "device-input",
        03         i18n("Gateway to Internet"),
        03         "combo",
        03         {"option1": "...", "option2": "..."},
        03     ),
        05 ]

        First argument is parameter keyword.
        Second argument is parameter label.
        Third argument is the name of widget set to be used.
        Fourth argument is options for third argument.


    def useModule(module, values):
        Activates specified module with given parameters. Values is a
        dictionary.
